1. Field of the Invention
This invention relates to a refrigerant compressor, and more particularly to a refrigerant compressor having a high-pressure chamber formed on an outer peripheral surface of a cylinder block, for reducing pulsations.
2. Description of the Prior Art
FIG. 1 shows the whole arrangement of a conventional wobble plate compressor. FIG. 2 is a view taken on line II--II of FIG. 1, while FIG. 3 is a view taken on line III--III of FIG. 1.
The compressor has a cylinder block 101 formed with a plurality of cylinder bores 106 which axially extend therethrough at predetermined circumferential intervals about a drive shaft 105. The cylinder block 101 has a rear-side end face thereof secured to a rear head 103 via a valve plate 102, and the rear head 103 is formed therein with a discharge chamber 112 and a suction chamber 113.
The cylinder block 101 has a front-side end face thereof secured to a front head 104. The front head 104 has a crankcase 108 formed therein, in which a wobble plate 110 is received.
The rear head 103, cylinder block 101 and the front head 104 are tightened in a longitudinal direction by a plurality of through bolts, not shown, extending via through holes 131, 134, to form a one-piece assembly. Some of the through holes 131 extend through spaces 132 formed for reduction of the weight of the compressor.
On an outer peripheral surface of the cylinder block 101, there is formed a high-pressure chamber 122 for reducing high-pressure pulsations. The outer peripheral surface of the cylinder block 101 is formed therein with a recess 101a. A cover 160 is secured to a rim of opening of the recess 101a via an O ring 153. The high-pressure chamber 122 is defined by inner wall surfaces of the cover 160 and the recess 101a of the cylinder block 101. The high-pressure chamber (second high-pressure chamber) 122 communicates with the discharge chamber (first high-pressure chamber) 112 via a communication passage 136 extending in parallel with the drive shaft 105 and an oblique hole 135 extending obliquely radially outward from the discharge chamber 112.
The valve plate 102 is formed with refrigerant outlet ports 116 for each communicating between a corresponding one of the cylinder bores 106 and the discharge chamber 112, and refrigerant inlet ports 115 for each communicating between a corresponding one of the cylinder bores 106 and the suction chamber 113.
The refrigerant outlet ports 116 are each opened and closed by a corresponding one of discharge valves 117 fixed to the rear head-side end face of the valve plate 102 together with valve stoppers 118, by a rivet 119.
A guide hole 127 is formed in the vicinity of the rivet 119, for communicating between the discharge chamber 112 and a bearing-receiving hole 125 formed within the cylinder block 101, via a restriction hole 126.
High-pressure refrigerant gas within the discharge chamber 112 is supplied to the bearing-receiving hole 125 via the guide hole 127 and the restriction hole 126, and then further supplied from the bearing-receiving hole 125 to the crankcase 108 via a bearing-receiving hole 128. As a result, oil within the refrigerant gas is supplied to thrust bearings 145, 146, radial bearings 147, 148 and so forth.
The flow of the refrigerant gas flowing out of the discharge chamber 112 is restricted by the oblique hole 135 and the communication passage 136, so as to reduce pulsations generated within the second high-pressure chamber 122.
However, since the high-pressure chamber 122 is formed on the outer peripheral surface of the cylinder block 101, it is required to use not only a connecting element, i.e. a pipe connector 150 for connection between the cylinder block side and the rear head side but also O rings 151, 152 for sealing between the pipe connector 150 and the cylinder block 101 and between the pipe connector 150 and the rear head 103, respectively, which results in an increases in the outer diameter and weight of the compressor (rear head 103) as well as an increase in the manufacturing costs of the same due to an increase in the number of component parts and elements.